XSB Src (SVN)-old

it is now possible to do things like
#if exists("file")
#include "file"
#else
#include "some-other-file"
#endif

A very useful conditional include idiom.

Numerous changes.

This update was motivated by the fix for a recently reported bug
in incremental tabling. The problem was incorrect maintenance
for the deleted field of callgraphs for facts, under certain
situations. However, there are other changes in this update.

-- I was in the process of making incremental tabling follow an
ISO-like semantics. While this feature is not turned on in
this version, it does contain a draft of the code, as well as
some refactoring that was needed to support the new
functionality under clang.

-- I also made some changes in the callnode structure so that the
subgoal to which dynamic facts correspond can be
reconstructed. I used this to find the bug above, but I also
want to use it to extend the incremental dependency predicates
in increval to also include dynamic facts.

-- Some changes introduced to quiet the Linux compiler made clang
complain. So I redid these changes as a macro,
SQUASH_LINUX_COMPILER_WARNING which is a no-op in clang, but
does what it did before in Linux.

-- As a final node, I had to move ctop_tag into
ptoc_tag_xsb_i.h (but did not change the file name).
Basically, I had to change the inline definition of this
predicate to static inline for clang. And since its used in
several files, I had to put it in a .h.

Added test of an incremental tabling bug reported recently by Javier Romero.

1. Added a banner option --nofeedback to block printing yess's and no's before
returning to top level.
2. In banner.P, added set_banner_control/2.

1. made gpp safe for cyclic #includes.
2. fixed the type of arguments for is_charlist in wrapping.P.
As a result, the testsuite now passes.
3. got rid of C warnings in the testsuite

make sure that included files are converted to their absolute file names

Add fail when initializing value for floundered_undefined/1 so it works
for batched scheduling (by not generating a cut over an incompleted table.)

(Try again to) fix intermittent bug in intern tabling.

Back out previous fix, since gcc barfs on it. Have to find a fix that
works there too.

Fixed (I hope) an intermittent bug in hash_cons (intern) processing.